Jadavpur University 2010 M.E Software Engineering Operating Systems in - Question Paper
Jadavpur University
M.E in Software Engineering
1st Semester Examination, 2010
Subject: Operating Systems
M. E. (Software Engineering) Examination, 20U
(I- Semester)
OPERATING SYSTEMS AND KERNEL PROGRAMMING
Time : Three hours Full MntV, . 100
Answer oy five questions.
a) Whal ad vantage t* there in having differcm time-quantum sizes on different level* of a multilevel feedback queue scheduling?
Many CPU scheduling algorithm are paramctcnd.( for example, the RR scheduling algorithm requires a parameter to mdttsfe the tmm sbee). One sei of algorithm may include another ( fur example, Ihe FfT* algnnthfli m Hr ** Igonthm with *n infinite
lime Jlice) What relallonthip holda between Ac Mkm* pmt of algorithm in term* of (heir own scheduling parameters
Priority A SJP PHndty A PTFS
FCFS A multilevel feed back qmct
) Consider n processes sharing the CPU in a rooad-*afcw Aatutning thal one
process to another process switch takes s seconds, vfeai wm* be the tone quantum size q
(5)
ingoish between deadlock prevention and deadlock miteot. (4)
X) A system may go from a safe state to an unsafe state" - Xesetfy yam answer. (4)
$ Is it possible to have a deadlock involving only ooe process? Explain yow answer. (2)
d) Consider a system consisting of m resources of the sane type, being shared by n processes. Resources can be requested and released by processes only ooe at a time. Show that the system is deadlock-frcc if the followings two consideration bolds -
i) The maximum need of each process is between 1 and m resources
ii) The sum of ail maximum needs is less than (m + n). (6)
t) Explain the necessary conditions to be deadlock. (4)
Explain the requirements that must be satisfied in a solution of a critical section problem.
V (4*
OastKiily define a semaphore with Us operations (3
c) Distinguish between deadlock and starvation. (}
d) A barber shop consists of waiting room with o chaos and ibe bwber room coraaimoa barber chair If then are oo customer! to be terved. the barter goes to deep, tf , customer enten the barber shop and ail chain are occupied, then the customer leave* the shop tf the barber is busy but chain are available, then the customer tits in one of the free chairs If the barber it asleep. the customer wakes up the barber Write procedure* to synchronize ihe barber and the cuttomen ((0)
1) How we can ensure that a circular wait situation will never occur among processes to access resources? Proof it (4)
b) A computer system has 6 tape drives, with n proctaaca competing far them Each process may need two tape drive* What M the minimum valise of a 10 he deadlock free system -Explain clearly (4)
|
c) Consider the following snapshot of Um tymm | |||||||||||||||||||||||||||||||||||
|
Is U possible to grunt the following requests
fVvaf# A 1)
(u) Process P4 requests (33,0)
(iii) Process P0 requests (0.2,0) (4H*4)
5. a) In a 4*lcvel paging system, the TLB is having hit ratio 98% aid mxcm time is 20ns. The memory access time is 100ns, then what will be the effective mesnory access time? (3)
b) Given memory partitions of 100k, 500k. 200k, 300k and 600k. (m ccder).
(i) How would each of the first-fit, best-fit and worn-fit algorithms place processes 212k.417k. 112kand426k(inorder)?
(ii) Which algorithm makes most cflkicnt use of memory tod why ? (6+2)
c) Explain why compaction always can not be done to overcome external fragmentation ? (3)
d) What are the cautes of thrashing 7 (2)
e) Including the initial parent process, bow many processes do the following program create*? (4)
votdtmin()
{
6. i) One of the parameter of a virtual memory system ts its page size. Give one advantage and Ota disadvantage of choosing a large page rate nfher than a mall one. (2)
b) What do you mean by pure demand paging ? Suppose you have devised a new page-Npiaoameat algwihm tmt you think must be optimal In some contorted test cases, Bafcdy'i anomaly occufi Is the new algorithm optumP -ExpUfci your answer (2+4)
o) Doe* the paging tyftera can eliminate both infernal and airrwl fragmentation? Justify your answer (4)
d) Suppote that page* in a virtual address spec* are referenced in the following order
l,2,l.3.2,l,4,Xl.U*4,lt$A2.l- There m three empty frame* available. Assume that paging decisions arc made on draand, 1t, whan page fault occurs Show the content of the frames aflat each memory reference, aamrmng the LJKU replacement poUey it used. How many page fata occur? (g)
7. Write *hort mrtes on any two of the following: (10+10)
a) Optimal page-rtplaccment algorithm
c) Inverted page-table
|
Attachment: |
| Earning: Approval pending. |
